The present invention relates to a self-contained outboard twin propeller adaptor. In the prior art, devices designed to convert power from a single shaft to plural propellers are known. The following prior art is known to Applicant:
U.S. Pat. No. 2,999,476 to Johnson discloses an outboard marine drive for an inboard engine of a boat. The device is designed to couple with the drive shaft of the inboard engine as it extends through the boat transom. This is different from the teachings of the present invention wherein the twin propeller adaptor mounts directly to the outdrive of an outboard engine and does not attach to the transom of the associated vessel.
U.S. Pat. No. 3,072,090 to Yarbrough discloses an outboard marine propulsion apparatus including twin propellers which mounts over the transom of a vessel and couples to the inboard drive shaft 11 of the vessel via a transmission 13 and upwardly extending drive shaft 14. Of course, this is different from the teachings of the present invention wherein a twin propeller adaptor attaches directly to the outdrive of an existing outboard motor.
U.S. Pat. No. 3,954,083 to Frostrom discloses a twin propeller stern drive mounted directly to the transom of a vessel and coupled to the drive shaft of an inboard engine. Again, the present invention differs from the teachings of Frostrom as contemplating attachment of a twin propeller adaptor directed to the outdrive of an existing outboard motor.